The present invention relates to (2-carboxy-3-hydroxy-propyl) -iminodiacetic acid and derivatives thereof. The present invention also relates to a process for the preparation of such compounds and their use as sequestering agents.
2--hydroxy--3--aminopropignic--N,N--diacetic acid and its derivatives are known from U.S. Pat. No. 4,827,014. Though these compounds are similar to the compounds of the present invention, they are structurally different and, as a result, the compounds of the present invention exhibit superior properties. This U.S. Patent also discloses a method for making these compounds, which method is significantly different than the method of the present invention. Finally, this patent points out that these compounds are useful as complexing agents, bleaching agent stabilizers and builders for washing and cleaning compositions.
U.S. Pat. No. 5,112,530 also discloses 2--hydroxy--3--aminopropionic acid derivatives and their use as complexing agents, bleach stabilizers and builders in detergent compositions.
U.S. Pat.No. 5,082,599 discloses 2--methyl--and 2--hydroxymethyl-serine --N,N--diacetic acid and derivatives thereof, and their use as complexing agents for heavy metal ions or alkaline earth metal ions and as bleach stabilizers or builders in detergents and cleaning formulations.
U.S. Pat. Nos. 5,019,296 and 4,973,730 also relate to the serine--N,N--diacetic acid and its derivatives, as well as methods for their preparation. Again, these compounds are used as complexing agents in detergent compositions.
The article, "Herstellung Einiger Neuer Komplexbildender Verbindungen und Bestimmung Ihrer Konstanten,"Erdey, L. et al, Acta Chim. Hung. Tomus, 21, pp. 327-332 (1959) discloses a method for preparing the complexing agents OL--Serine--N--diacetic acid and L--Glutaminic acid--N--diacetic acid and the measurement of the dissociation constants thereof.
Published European patent application 0 516 102 discloses biodegradable chelants comprising sulfonate groups and compositions thereof. Typical compounds include glycine--N--2--hydroxyethyl--N--2--hydroxypropyl sulfonic acid and nitrilo--N,N--bis(carboxymethyl)--N--2--hydroxypropyl sulfonic acid. Also disclosed are numerous uses for biodegradable chelants. The sulfonic acids, salts and complexes, as disclosed, are not subject matter of the current invention.
Finally, 2--((((1,1--dimethylethoxy)carbonyl) (phenylmethyl)amino)methyl) --3--hydroxy butanoic acid is known from Chemical Abstract No. 98768--24--2 , and a-((((1,1--dimethylethoxy)carbonyl)(phenylmethyl)amino) methyl)--.beta.--hydroxy--benzenepentanoic acid is known from Chemical Abstract No. 98768--23--1. These materials are significantly different from the materials of the present invention since they contain a phenylmethyl substituent substituted on the nitrogen atom.
While the foregoing publications disclose several compounds which are useful as sequestering agents, none of these materials combines a high level of activity as a sequestering agent with a good biodegradability. Accordingly, the primary object of the present invention is to provide novel compounds which are biodegradable and which exhibit excellent sequestering capabilities.
The foregoing sequestering agents also suffer from the disadvantage that they require complex synthesis processes which make them impractical for large-scale commercialization. Accordingly, it is a further object of the present invention to provide a method for making biodegradable sequestering agents which is simple and which can be scaled up for large-scale production.
These and other objects of the invention will be apparent to the man of skill in the art from the summary and detailed description which follow.